Thanks for the Service Sumary. I have checked the water level and yes it fills to the same amount the bottom drawer (which works fine) fills to. Does this mean controler is faulty? Do you have instructions on replacing said controller and is it possible to swap controller from bottom unit to test theory?

Thanks for all the advice. I have now done the following with no change:
- swapped rotor
- swapped rinse arm
- swapped controller
DADoESTX, mentioned the fill level is sensed by the rotational load on the pump impeller. Is there a sender unit I need to look for? As it stands now, the top drawer stops at 113, 101, 94, 44, 38, and 14 minutes on the normal cycle and shows the U1 fault. I wonder if these times correlate to water fill point in the cycle.

Well I got a hold of the nice people at F/P and they gave me an important bit of info,"the tub needs to fill in under 45 seconds". This wasn't happening and it was just taking too long to fill the tub. Replaced fill solenoid and all is well now. So turns out J5 was right with the flow rate check just needed to know what a descent rate was.